This invention relates to a device for pulling and removing the aluminum tube (DROP TUBE) that is used inside of the 4-inch pipe that extends up from the underground gasoline tanks at service stations. Corrosive sediments settle in around the outside of the tube and on the inside of the 4-inch pipe and wedge it tight. The tube is often destroyed by the efforts of the workers in the process of removing it.
A worker usually drives a crow bar down in between the outer wall of the tube and the inside wall of the 4xe2x80x3 pipe. He then pierces through the wall with the crow bar and pries it from side to side and upwardly until it up far enough to get a wrench on it where greater gripping force can be applied to it. The Drop Tube has a float flapper in it to prevent over filling of the tank. It is riveted and glued and sealed to the aluminum tube and it is not practical to try to salvage the valve by removing it from the tube. The cost of new Drop Tube is in the range of $325.-$350. Therefore, being able to remove a tube without destroying it is of significant economic importance.
There is no tool available on the market that I can find that is or has been made to insert into a tube and engage or grip it sufficiently to break it loose when it is stuck tight. Contractors and suppliers that I have contacted to not know of any device that even attempts to do this. Their response was that it is about time.
I have not been able to find anything in the prior art that is similar or works like my invention.
Some of the ways I have used this basic principle of a tapered body and a wedging slip is shown in my patents whose numbers follow. The wedging principle was used long before any of my uses. In all of applicant""s applications and the one I saw used in the oil industry were used to hold a string of tubing from being pushed out of the oil well casing or to support the weight of the tubing and keep it from moving down into the well. Usually there was a rubber packer that was sealing off between the tubing and the casing do that there was a hydraulic force pushing the tubing one way or the other.
The wedging principle is an effective blocking means to prevent upward or downward movement of the tubing string in an oil well.
In all of the applications and those that I know about, the setting of a wedge into a body has always been either by hydraulic actuation within the tubing or casing or by the machinery of the rig at the surface of the well. In the latter case, it was done by rotating the tubing string and lowering or raising the string vertically and or a combination of the two. With my device a person inserts it into the tube manually by hand and manipulates the setting of the tool by simply pulling straight up on the pulling means which sets it into gripping or contacting engagement with the tube to be removed. It is a tube removing tool that is greatly needed. The forces trying to overpower the wedging mechanism of applicant""s device do not originate within the tube as they do in an oil well, but they originate with a person pulling on a pulling means. And further, the pulling means that applicant uses is not intregal with the body of the wedging part as the pulling means is in an oil well.
And further, none of the prior art had a jarring capacity or feature like applicant""s devise does. With applicant""s devise the setting is done by the hands on installing, pulling and jerking of a personal operator.
Applicant""s patent Nos. using a wedging mechanism to block vertical tubing movement in an oil well are: U.S. Pat. Nos. 2,786,534 and 3,045,755 and 3,252,476 and 3,662,824 and 3,299,955 and 3,313,350.
The major object of applicant""s invention is to provide a device that will operate inside of a tube and grip it sufficiently to allow forces to be transmitted to the tube by the pulling, jarring action exerted by an operator at the surface. The jarring feature is a significant aid in breaking loose a stuck tube without damaging it. It will save the destruction of many tubes. It will save many thousands of dollars. It will save the contractors who have to remove these tubes many ours of labor. It will solve an aggravating problem.
This devise incorporates a METHOD of manually manipulating a tool that will engage or grip a tube and jar it loose by a unique jarring feature and remove it from its stuck position.
The method of operation is that the operator lowers the pulling means 20 into the tube 23 a few inches. The pulling means 20 carries the body 21 in with it. The wedge 25 follows in behind the body 21 onto the tapered surface 24 of the body 21. The wedge 25 is then trapped between the body 21 and wall of the tube 23. A stop on the bottom end of the pulling means 20 supports the body 21.
The operator pulls up on the pulling means 20 to lift the body 21, which forces it into wedging engagement between the wedge 25 and the wall of the tube 23. The taper 24 on the body 21 and the wedge 25 is a locking taper so when the pulling means 20 is lowered, the body 21, and wedge 25 stay put. Then when the operator pulls upwardly on the pulling means 20 with a fast execration, it creates a much greater peak force than can be obtained by just pulling hard on the pulling means 20.
If the pulling means 20 is a steel cable, the jarring effect is accomplished by using any heavy shaft, pipe or wrench that the operator may have among his tools. The shaft is inserted into a loop 20a at the upper end of the pulling means 20. Then the operator lowers the shaft. Then a fast upward pull on the shaft by the operator creates a peak upward impact on the pulling means and into the body 21 and the tube 23.